Key interlock



Oct. 25, 1949. I B. CARLSTROM ETI'AL KEY INTERLOCK 4 Sheets-Sheet 1 Filed April 27, 1944 Oct. 25, 1949.

KEY INTERLOCK Filed April 27, 1944 4 Sheets-Sheet 2 m N 3w Oct. 25, 1949. B. CARLSTROM E'IIAL KEY INTERLOCK 4 Sheets-Sheet 3 Filed April 27, 1944 Oct. 25, 1949. B. CARLSTROM ETAL I 2,485,695

KEY INTERLOCK Filed April 27, 1944 4 Sheets-Sheet 4 INVENTORS 4% W ATTORNEY Patented Oct. 25, 1949 UNITED STATES PATENT OFFICE KEY INTEELOCK Bengt Carlstrom and Erik Grip, Atvidaberg, Sweden, assignors to Aktiebolaget Facit, Atvidaberg, Sweden, a corporation of Sweden Application April 2'7, 1944, Serial No. 532,961 In Sweden November 30, 1942 Section 1, Public Law 690, August 8, 1946 Patent expires November 30, 1962 9 Claims. (01. 235-130) 2 those parts are shown which are nearest to the observer, that is nearest to the plane of drawing.

In this specificationwhen not otherwise expressly statedthe expressions right, left, upwards, downwards, forward, backward are used to indicate these directions as they appear to an operator sitting at the key-board of the machine.

The machine to which this invention is applied in accordance with the annexed drawings, is in its principal features constructed in accordance with U. S. Patents Nos. 2,108,596 and 2,243,075, though the invention is by no means limited to that type of machines. The results register and In modern calculating machines for all the four fundamental arithmetic problems (addition, subtraction, multiplication and division), sometimes called multiplying machines, with ten amount or numeral keys for the numerals 0, 1, 2, 3 8, 9, locking devices are necessary to prevent an incorrect manipulation.

The chief purpose of this invention is to provide the machine with such locking devices that it is impossible simultaneously to manipulate two or more control members adapted to release incompatible functions, that is functions which will cause the machine to jam or will give rise to other faults in the machine when simultaneously released. the revolutions counter may be cleared by hand Another purpose of this invention is to provide (See U. S. Patent 2,188,748) while the actuator or f r Such locking devices t fter t manieusetting mechanism may be cleared in accordance lation of a control member, such as a key, only With 3 Patents 1,927,771 d The that or those of the other control members may machine may have an electric driving mechanism be manipulated which will effect the desired rein aCcordance WiJPh Patents 2,068,399 sult, that is: whose function is compatible with and 2,127,102, W fle the control mechanism may the calculating Operation initiated or prepared be constructed 1n accordance with British Patent by the manipulation of said first-mentioned con- 551,31} Patents 23398286 and trol 2,243,075, issued, respectively, on April 9, 1946, and Another object of this invention is to provide May 1941' Certain parts in the specification a locking device for the motor keys of a powelu below carry the same reference characters as the operated multiplying machine having numeral corresponding parts of the three last-mentioned and shifting keys and also one or more clearing patents mechanisms for the registers or counters, for the n The machlile shown m the drawmgs has purpose of locking said clearing mechanisms in i or pm'wheel 1 (not Show?) whmh their inoperative position when the motor key is Journalled on the main shaft 5 and 1s settabl e is depressed or Vice versa. by means of ten numeralkeys 200. In addi- Another purpose of this invention is to effect machme shlftmg keys such locking in a simple and reliable manner. T rlghtste-p-shlftlng key moves the car- One embodiment of the invention is illustrated Rage of pm wheel rotor one Step to the fight when said key is depressed. When depressed, m h annexed g the left-step-shifting key I99 moves said carriage 1 shows a frfmt of f m lmportant one step to the left (via intermediary members), parts of the locking mechanism 111 accordanse in well-known manner. When depressed, the thlsrllnventlon-t 1 V t ILJI tabulatir g key l98 causes said carriage to be 2 S 0W5 aver lea sec on 9 me moved directly to its extreme left position (for m F g. 1. division). The machine also has a multiplication F1g. 3 shows a vertical view substant ally in the key I (positive mmti revolutions key) and a dllefitlon of the arrow mfirked In division key 2 (negative multi-revolutions key), Flg. 4 shows the parts illustrated in Fig. 3, seen by means of which the pin wheel rotor is Started f f belowto perform one or more revolutions in its posi- ShOWS a Dartlal VIEW n vlew) 1n the tive and negative direction of rotation, respecdireetion of the arrow marked V m Fl t tively, that is, counterclockwise and clockwise, Fi 6 h w a i n n the li V VI m respectively, in Fig, 5. Those directions are indi- Fig. 5. cated by the arrows marked and in Fig. 5. Fig. '7 shows the actuator clearing key and ad- In addition, the machine has a chief control lever jacent parts. 294 for setting the machine to automatic division In the drawing only those parts are shown and to multiplication with shifting to the right which are necessary for illustrating this invenand to the left, respectively; see British Patent tion, For attaining clearness, in some cases only No. 551,311 or U. S. Patent No. 2,398,286. The

lever 20I is rockably journalled on the stationary pin 205 secured to the machine frame.

The numeral keys 200 cooperate with rockable locking pawls 490 journalled on the stationary rail M which forms a part of the frame of the machine. In that rail guiding slots are cut for the keys 200, I91, I98. Due to the action of the pawls 499 only one of the numeral keys 200 can be depressed simultaneously.

On the rail 50I a locking bar 502 is slidably journalled on screws or studs 503 entering oblong slots in said bar. A tension spring 504 normally holds that bar in its extreme right position (position of rest). The bar 502 extends along the front side of the machine and it has channels or slots 502a for each of the keys I 91-200 ermitting said keys to swing freely upwardsand downwards, when the bar is in its position of rest. On its right end the bar 502 has an oblique surface 502b, engaged by the forward end of a lever 505, as shown in Figs. 1 and 5. This lever 505 is rotatably journalled on the pin 35 and carries at its rear end a pin or stud 505a, normally resting in a recess 33Ia of an angular member or contact lever 33L which is rotatably journalled on the stationary pin 333. When said lever is rocked due to the depression of either of the keys I, 2 it closes a contact for the electric current to the driving motor, in well-known manner.

The lever 33I has a bent portion 33I b extending across the rear ends of the keys I, 2 and also across the locking arm 3| 0. Said arm is rotatably journalled on the pin (key shaft) 35 and carries a roller 309 engaging the periphery of the cam disc 308 rigidly secured to the main shaft 5. In the drawings the reference character 3I0a indicates that part of the locking arm 3I0 which extends below the bent portion 33Ib.

The elements shown in Fig. 7 and numbered 380, 392, 398, 401, 4H and 4I2 are the same elements as those described under the same reference characters in United States Patent No. 2,398,286 wherein said elements are described in detail.

To prevent the simultaneous depression of the keys I, 2, a pointed pawl 500 (Figs. 5 and 6) is rotatably journalled on the pin 5I3, secured to a stationary guiding member 5I4 for these keys. The piece 5I4 forms a part of the frame of the machine.

At its left end the bar 502, when displaced to the left, can just pass below the point 5I5a of a locking arm 5I5 which is rotatably journalled on the shaft 5I9. At 5I5b this locking arm is recessed along a curve, and in this curved recess there normally rests the nose 5I6a of the clearing arm 5I6, rotatably journalled on the shaft 5I'I. By preference, one clearing arm 5I6 is arranged on each of the clearing shafts of the results register and of the revolutions counter, said two clearing arms actuating the locking arm 5I5 either separately or in unison. (The clearing arm 5 I6 may have the construction shown at I in U. S. Patent No. 2,188,748.) A tension spring 5I8 presses the locking arm 5I5 to engage the clearing arm 5I6.

The locking arm 5I5 has a part 5I5c directed downwards which under the action of the spring 518 engages a projection of a locking arm 209 which is rotatably journalled on the fixed pin 2| I. A tension spring 2I0 presses the pin 20911 of the rocking arm 209 to engage either of three notches or recesses Ia of the chief control lever 20L Said three recesses correspond to the setting of the lever 20I to automatic division, to multiplication with automatic step shifting to the left and to multiplication with automatic step shifting to the right.

The key-operated setting arms 3I (see U. S. Patent No. 2,108,596) for the pin Wheels are rockable on a shaft 520 under the action of the numeral keys 200 which have curved slots 39 in their back ends to engage pins 38 on the setting arms 3I A shaft 44 which is rotatably journalled in the machine frame and also has the same functions as the shaft 44 shown in U. S. Patent No. 2,243,075, carries arms 52I (Fig. 2), one in front of each of the three keys I 91-I99. Each of said arms 52I is rigidly secured to the shaft 44 and has a stud 522 engaging a cam surface 523 on the respective keys I91-I99 (only the key I91 is visible in Fig 2). To the shaft 44 a locking member 524 is secured just opposite the two setting arms 3I (said arms being common to all the numeral keys 200), and said member 524 cooperates with pins 525 on said setting arms 3I. In the position of rest, that is when none of the keys I 91-!99 has been depressed, the locking member 524 is in its position shown in full lines in Fig. 2 and does not lock the setting arms 3|. Consequently, numerals (items) may be entered into the pin wheel rotor by means of the keys 200. But when one of the shifting keys I91-I99 is depressed, the locking member 52 is swung to its position shown in dash-and-dot lines in Fig. 2 so that the setting arms 3! and consequently also the numeral keys 200 are locked. As described in U. S. Patent No. 2,243,075 the shaft 44 then remains in its position as set, that is in its operative position, until the pin wheel rotor is cleared. At the clearing, the shaft 44 and the locking member 524 return to their positions of rest.

The device described acts as follows:

When one numeral key has been depressed, the other numeral keys are locked by the locking pawls 493 and cannot be depressed. Similarly, when one of the keys I, 2 (together with addition and subtraction keys possibly connected to them) has been depressed, the locking pawl 500 prevents the other from being depressed. But the shifting keys I91-I09 may be simultaneously depressed, but this does not imply any risk or any particular inconvenience; if two of said keys are depressed simultaneously, they either counteract each other or will render the shift that one of them would effect separately; but this does not cause any risk of damage or jamming of the machine and it is consequently not necessary to prevent those keys from being depressed simultaneously. The chief control lever 20I may be manipulated, while simultaneously a numeral key 200 or shifting key I91-I99 is depressed. This is desirable, because the functions originated by the manipulation of the lever 20I and of the keys I91-200 are compatible and independent of each other.

As soon as any of the keys I91-I00 has been depressed, the setting arms 3I and consequently also the numeral keys 200 are locked by the locking member 524. But if any of the numeral keys 200 is depressed, the pins 525 are rocked into the path of motion of the locking member 524 so that no shifting key i91-l99 can be depressed, be fore the numeral key has returned to its position of rest.

As soon as a control key I or 2 is depressed, it swings the contact lever 33I clockwise in Fig. 5, so that the pin 505a is lifted out of the recess 33 Ia. This causes the arm 505 to swing downwards towards the oblique surface 50 21) in Fig. 1 so that the bar 502 is displaced to its extreme left position (locking position); this looks all the shifting and numeral keys lQI-Ztt and also-via the locking arm Eilthe arm 5% and consequently the whole clearing mechanism for the registers. Simultaneously also the chief control lever 21 is locked via the arm M50 which keeps the looking arm 2% with its pin 2mm in the recess 20m into which it has been set, thus rendering it impossible to rock the arm 29!. The bar 502 is kept in its locking position by the arm 505 as long as the pin wheel rotor rotates, because as soon as the pin wheel rotor is started due to the depression of either of the keys I, 2, the cam disc 308 on the shaft 5 of that pin wheel rotor rocks the releasing arm 3N3. Consequently the part 3llla of that arm engages the bent portion 33 lb of the contact lever 33% from below so that said lever cannot return to its position of rest, until the operator has taken off his finger from the depressed key I, 2 and thereafter the pin wheel rotor has completed its current revolution just going on. Then the roller 3% enters the lower portion of the cam disc 368 and the rotor is stopped in wellknown manner.

If one of the numeral or shifting keys I9'l-20ll is depressed or if the clearing arm 5% is rocked, the bar 582 will be locked in its extreme right position and then itself via the arm 5B5 locks the contact lever 3M and thus also the two control keys l, 2. If (incorrectly) the chief control lever 20! remains standing in such intermediate position that the pin 2568a does not rest on the bottom of one of the recesses title but rests upon the top of one of the tongues between them, the locking arm 26!) is rocked upwards in Fig. 4, that is backwards in the machine. This causes the lever M5 to be rocked counter-clockwise in Fig. 3 so that its part 515a enters the path of motion of the locking bar 5512 and prevents it from being displaced to the left. This means that the control keys l, 2 are locked when the chief control lever 2th is not correctly set into one of its three operative positions.

It is to be observed that when an addition key or a subtraction key or analogous member is coupled to the multiplication key l or to the division key 2, respectively, such addition or stubtraction key or analogous member is locked and causes locking in just the same manner as the multiplication or division key, respectively, connected therewith and controlled thereby (see British Patent No. 551,311 or U. S. Patent No. 2,398,286).

If special clearing key 4%, as shown in Fi '7 (which corresponds to key this in the British Patent No, 551,311 or U. S. Patent No. 2,398,286 is sued April 9, 1946), for the pin wheel rotor is provided, this clearing key when manipulated, rocks the contact lever 33E clockwise in Figs. 5 and 1, as described in detail in the patent just mentioned. In the manner indicated above the lever 33! then displaces the bar 5112 to the left so that the keys I til -2% and the clearing member 5H3 are locked. Reversely, the particular clearing key 406 for the pin wheel rotor is looked, as soon as any of the members Eel-2B0 and 5H5 has been manipulated and consequently the bar 5&2 has been locked in its right position.

What we claim is:

1. In a power operated multiplying machine rotatable in two directions under the control of two motor keys one for each direction of rotation and having a register, in combination, a locking member cooperating with said motor keys to pre- Vent the simultaneous manipulation thereof, numeral keys for setting items, shifting keys, members kinematically connected with said numeral, motor and shifting keys, a slotted slidable looking bar movable into the paths of motion of said members kinematically connected with said numeral, motor and shifting keys and normally held out of said paths, said locking bar having an oblique edge in the path of motion of said members kinematically connected with said motor keys to cause slidable displacement of the locking bar by depression of either motor key and thereby prevent said numeral and shifting keys from being depressed when one of said motor keys is depressed, said slidable locking bar being held in normal position by said members kinematically connected to said numeral and shifting keys when one of said numeral keys or said shifting keys is operated to thereby prevent operation of the motor keys, and a register clearing initiating device, said locking bar cooperating with said clearing initiating device to prevent it from being manipulated when one of said motor keys is depressed, said clearing initiating device locking said slidable bar in normal position to thereby prevent depression of one of said motor keys when said clearing initiating device has been operated.

2. In a power operated multiplying machine rotatable in two directions under the control of motor keys one for each direction and having a register, in combination, a locking member for said motor keys to prevent the simultaneous manipulation thereof, numeral keys, shifting keys, a register clearing initiating device, members kinematically connected with said numeral, motor and shifting keys and "with said register clearing initiating device, and a slotted slidable locking bar in the path of motion of said members kinematically connected with said numeral motor and shifting keys and with said clearing initiating device, said locking bar having an oblique edge in the path of motion of said members kinematically connected with said motor keys to cause slidable displacement of the locking bar by depression of either motor key to prevent said numeral and shifting keys and said clearing initiating device from being manipulated when one of said motor keys is depressed, said locking bar being held in its unoperated position by said members connected to said numeral and shifting keys to thereby prevent operation of said motor keys when said shifting or numeral keys have been operated.

3. In a power operated multiplying machine rotatable in two directions under the control of motor keys for either direction of rotation and having a locking member for said motor keys to prevent the simultaneous manipulation thereof, numeral keys for entering items, shifting keys for effecting denominational shifting, and a register clearing initiating device, in combination, members kinematically connected to the numeral, shifting and motor keys and a longitudinally slidable locking bar in the paths of motion of said members in kinematic connection with said numeral, shifting and motor keys and with the clearing initiating device, said locking bar having slots for all of said kinematically connected members, the slot for the member kinematically connected with said motor keys having an oblique edge whereby said locking bar is displaced and locks said numeral and shifting keys and said clearing initiating device against manipulation when one of said motor keys is depressed and whereby displacement of said locking bar is prevented upon operation of either said numeral or shifting keys or said clearing initiating device to thereby prevent operation of either of said motor keys.

4. In a multiplying machine rotatable in either direction by an electric motor, the electric circuit or" which is under the control of two motor keys one for each direction, the machine having numeral keys for entering items into said machine, shifting keys for effecting denominational shifting, register clearing initiating device, and a contact lever engaged by said motor keys to close the electric circuit, in combination, a second lever engaging said contact lever and a slotted locking bar in the paths of motion of said second lever and of the numeral and shifting keys and the clearing initiating device to prevent the nuineral and shifting keys and the clearing initiating device from being manipulated when one of the motor keys is depressed, said locking bar being held against displacement when one of the numeral or shifting keys or the clearing initiating device is operated to thereby prevent operation of said second lever and of the motor keys.

5. In a multiplying machine having an actuator rotatable in either direction by an electric motor the electric circuit of which is under the control of motor keys, one for each direction, in combination, numeral keys for entering item's, shifting keys for denominational shifting, a reg ister initiating clearing device, a contact lever engaged by said motor keys to close the el ctric circuit, a second lever engaging said contact lever, a. clearing key engaging said contact lever and adapted to control the clearing of said actuator, and a slotted locking bar in the paths of motion of said second lever and of said numeral and shifting keys and of said clearing initiating device, said locking bar having an oblique edge in the path of motion of said second lever to cause slidable displacement of the locking bar by depression of either motor key, to prevent said numeral and shifting keys and said register clearing device from being manipulated when said clearing key is depressed, said locking bar being held against displacement when one of said numeral or shifting keys or said register clearing initiating device is operated to thereby prevent operation of either of said motor keys.

6. In a power operated multiplying machine rotatable in two directions under the control of motor keys one for each direction, and having numeral keys for entering items into said machine, shifting keys for denominational shifting, a register clearing initiating device, a control lever for setting the machine to automatic division and to multiplication for automatic step shifting in either direction, in combination, members operatively connected with said numeral, shifting and motor keys, a member in operative connection with clearing initiating device and a slotted locking bar in the paths of motion of said members in operative connection with. said numeral, shifting and motor keys and with said member in operative connection with said clearing initiating device and with the control lever to prevent the numeral and shifting keys, the clearing initiating device and the control lever from being manipulated when one or" the motor keys is depressed.

7. In a power-operated multiplying machine rotatable in either direction under the control of motor keys, and having numeral keys, shifting keys for denominational shifting, a register clearing initiating device, a control lever for setting the machine to automatic division and to nlultiplication with automatic step shifting in either direction, in combination, members opera'tlvely connected with the numeral, shifting and motor keys and with the register clearing initiating device, a slidable slotted and cam ended locking bar in the paths of motion of said members in operative connection with said numeral, motor and shifting keys, a locking arm having three parts, said parts being in operative connection with said locking bar, said register clearing initiating device and said control lever to prevent said numeral and Shifting keys and said clearing initiating device and said control lever from being manipulated when one of motor keys is depressed, said parts of said locking arm preventing displacement of said locking bar to thereby prevent manipulation of said motor keys when either said numeral or shiftin keys or said clearing initiating device been operated.

8. In a power operated multiplying machine having two motor keys for setting the machine to rotation in either direction, setting arms for entering items into the machine, numeral keys acting on said setting arms, locking pawls cooperating with said numeral keys for preventing simultaneous depression of more than one of them, shifting keys for eiiecting denominational shifting and a register clearing initiating device, in combination, members kinematically connected to the numeral, shifting and motor keys, a locking member for the setting arms, said locking member being under the action of said shif ing keys to lock said setting arms, and a slotted cam ended locking bar in the paths of motion of said members in kinematic connection with said numeral, motor and shifting keys and with said clearing initiating device to prevent said numeral and shifting keys and said clearing initiating device from being manipulated when one of said motor keys is depressed due to movement of said locking bar resulting from coopera tion of the cam end thereof with members connected with said motor keys, said locking bar being locked against displacement when said numeral or shifting keys or said clearing initiating device is manipuated to thereby prevent movement of either of said motor keys.

9. In a power operated multiplying machine having motor keys for setting the machine to rotation in either direction, setting arms for entering items into the machine, numeral keys acting on said setting arms, locking pawls cooperating with said numeral keys for preventing the simultaneous depression of more than one of them, shifting keys for effecting denominational shifting and a register clearing initiating device, in combination, members kinematically connected to the numeral shifting and motor keys, a. shaft, 9, locking member on said shaft, arms on said shaft, said arms being engaged by oblique surfaces on said shifting keys to lock said arms when one of said shifting keys is depressed, and a slotted cam ended locking bar in the paths of motion of said members in kinematic connection with said numeral, motor and shifting keys and said clearing initiating device to prevent said numeral and shifting keys and said initiating device from being manipulated when one of said motor keys is depressed and to prevent said motor keys from being manipulated when any of said numeral keys or said. shifting keys or said clearfile of this patent:

UNITED STATES PATENTS ing initiating device is operated. Number Name Date 1,900,103 Gubelmann Mar. 7, 1933 BENGT CARLSTROM. 5 1,905,807 C Apr. 25, 193 ERIK GRIP, 1,906,063 Hilder Apr. 25, 1933 1,968,898 Kurowski Aug. 7, 1934 REFERENCES CITED 1,973,313 Hart Sept. 11, 1934 2,269,644 Bratt Jan. 13 1944 The followin references are of reco d n th g r 1 e 10 2,330,689 Crosman Sept. 28, 1944 

